In June 1940, after the fall of France, ground operations in Europe came to a halt. Henceforth, only the battles taking place in the sky and at sea would provide evidence that a war was still being fought. For the first time in modern history, naval and air forces alone would determine the outcome of a large-scale armed conflict. Whilst the opposing warships clashed only occasionally, the air war began to dominate events due to its intensity and the numbers involved.Following the defeat of the Allies on the continent, two armies faced each other – the battered remnant of the British Expeditionary Force and the hitherto invincible German war machine. The two were separated by the English Channel, a strip of open water approximately a dozen kilometres in width at its narrowest point. Realizing that they stood little chance at sea against the mighty Royal Navy, the Germans knew that the key to defeating Great Britain lay in achieving air superiority. There was no doubt on either side of the Channel that victory in the forthcoming battle would go to whichever side controlled the airspace over the contested area.The Battle of Britain proved to be a turning point in the war for Europe. It was the Luftwaffe’s first major failure, and a portent of things to come. Although not entirely defeated, it suffered an unacceptably high rate of attrition, and the morale of its personnel suffered accordingly. No fewer than 2,500 German airmen were killed or captured in the battles over the Channel. They constituted the core of the Luftwaffe’s most experienced and best-trained cadres. Such crippling losses were never made good, despite the Germans implementing a massive and competent training program. Officially, the Battle of Britain, as it came to be known, lasted from 10th July to 31st October 1940. Obviously, clashes took place both before and after that timeframe, albeit on a reduced scale. Most sources agree on four main phases of the battle:– Phase I (known to the Germans as the Kanalkampf) started on 10th July 1940 with the first major Luftwaffe air raids against coastal shipping;– Phase II, commencing on 12th August, saw the Luftwaffe focus on airfields and industrial targets;– Phase III heralded the bombing of civilian targets, including London;– Phase IV, dated from 7th to 31st October, witnessed the Luftwaffe daylight offensive fizzle out in favour of night bombings.On 17th October 1940 Hitler decided to postpone the invasion of Great Britain indefinitely. However, German air operations across the Channel continued. Having been curtailed by unfavourable weather conditions during the winter of 1940/41, the air war over the Channel front flared up again in May 1941. During that month the Luftwaffe launched its last massive air raid against London, despatching some 700 aircraft. Shortly afterwards the Germans shifted their attention to the east by starting the war with the Soviet Union.By July 1940 the Luftwaffe had amassed some 2,700 frontline aircraft for the imminent air battle with Great Britain. Sources vary as to the actual composition of this formidable force. Len Deighton mentions 1,260 bombers, 316 Ju 87 dive-bombers, 893 Bf 109 single-engined fighters and 280 Bf 110 twin-engined fighters. The Germans were supported by a somewhat token contingent sent by the Italian Regia Aeronautica, amounting to 180 aircraft.Reichsmarschall Herman Göring slated three of his five Air Fleets (Luftflotten) for the task. Generalfeldmarschall Albert Kesselring’s 2nd Luftflotte was to bear the brunt of the fighting, being assigned to cover the London area and counties along England’s southern coast. Generalfeldmarschall Hugo Sperrle’s 3rd Luftflotte was to operate over the southwestern coast, mainly against the port areas of Bristol, Plymouth and Southampton. Furthermore, Generaloberst Hans-Jürgen Stumpff’s 5th Luftflotte was to add its weight to the onslaught by launching attacks from Norway and Denmark against the eastern coasts of England and Scotland. All the participating units had been resupplied after the campaign against France; most were rearmed with the latest equipment, and their personnel rosters were up to their authorized strength. The fighter units (Jagdgeschwadern) were to rely on their combat-tested Messerschmitt Bf 109 Es and Messerschmitt Bf 110 Cs. The bomber units (Kampfgeschwadern) had a wider variety of types on strength: Dornier Do 17s (mainly of the Z variant), Junkers Ju 88s and Heinkel He 111s. The dive-bomber units were equipped with Junkers Ju 87s. The notorious Stukas were to suffer devastating losses in the forthcoming battle, a fact that would effectively end the legendary status they had acquired during the early phase of the war. The Luftwaffe sporadically deployed other types of aircraft throughout the battle, but their importance was marginal.